As mailbox archives continue to grow due to retention policies, legal requirements, or business needs, administrators may eventually reach the limits of a standard Online Archive.
To address this, Exchange Online provides the Auto-Expanding Archive feature, which automatically increases archive storage capacity when needed, helping organizations maintain compliance and avoid storage limitations.
In this article, we’ll look at how to verify whether Auto-Expanding Archive is enabled for a mailbox and how to activate it using PowerShell.
Prerequisites
Before running the required commands, connect to Exchange Online PowerShell:
Connect-ExchangeOnline
If you do not already have the Exchange Online Management module installed:
Install-Module ExchangeOnlineManagement
Verify the Auto-Expanding Archive Status
To check whether Auto-Expanding Archive is enabled for a mailbox, run:
Get-Mailbox user@domain.com | FL AutoExpandingArchiveEnabled
Example Output
AutoExpandingArchiveEnabled : True
If the value returned is True, then Auto-Expanding Archive is already enabled. If the value is False or blank, the feature is not currently active.
Enable Auto-Expanding Archive
To enable Auto-Expanding Archive for a mailbox, run:
Enable-Mailbox user@domain.com -AutoExpandingArchive
Once the command has been executed successfully, Exchange Online will begin enabling the feature.
Note: Activation is not immediate. Depending on the Microsoft 365 environment, it may take several hours before the change is fully applied.
Verify the Activation
After allowing sufficient time for the change to propagate, run the verification command again:
Get-Mailbox user@domain.com | FL AutoExpandingArchiveEnabled
When the output shows:
AutoExpandingArchiveEnabled : True
the feature has been successfully enabled.
When Should You Use Auto-Expanding Archive?
Auto-Expanding Archive is particularly useful in the following scenarios:
- Users with large volumes of email.
- Organizations with long retention requirements.
- Microsoft 365 environments subject to compliance or legal hold requirements.
- Shared mailboxes that accumulate significant amounts of data.
- Businesses that want to avoid manual archive storage management.
Conclusion
Auto-Expanding Archive is a valuable Exchange Online feature that automatically increases archive storage capacity as mailbox archives grow.
With a single PowerShell command, administrators can ensure that archive mailboxes continue to expand seamlessly, reducing administrative overhead while supporting long-term retention and compliance requirements.